First T20, East London
South Africa 142-5 (20 overs): De Klerk 29* (16); Dean 2-20
England 143-6 (19.2 overs): Sciver-Brunt 59 (54); Marx 3-19
England won by four wickets
Nat Sciver-Brunt's composed half-century led England to a four-wicket win over a depleted South African side in East London.
Chasing 143, Sciver-Brunt fell for 59 in the final over with the scores tied but Sophie Ecclestone scampered a leg bye to secure the victory with four balls to spare.
South Africa were in a strong position when England needed 57 from the final six overs on a slow pitch, but Sciver-Brunt and Amy Jones smashed 22 from Ayanda Hlubi's 15th over to change the course of the game.
Jones fell for a crucial 31 from 19 balls in the following over, but South Africa's attack struggled without three of its frontline bowlers in Marizanne Kapp, Ayabonga Khaka and Chloe Tryon, who were rested.
Nadine de Klerk stepped up with 2-20 while seamer Eliz-Mari Marx took 3-19, but the recent T20 World Cup finalists were left to rue their sluggish start with the bat.
In the absence of two of their experienced batters in Kapp and Tryon, the Proteas' remaining senior players were guilty of squandering good starts with captain Laura Wolvaardt making 22, Tazmin Brits 15 and Anneke Bosch 18, while Sune Luus fell for a duck.
Annerie Dercksen held the innings together with 26 from 29 balls before De Klerk's impressive cameo of 29 from 16 provided a much-needed late flurry of runs to post 142-5.
It looked a competitive total on a turning pitch but Sciver-Brunt's class proved the difference for England, who take a 1-0 lead in the three-match T20 series before three one-day internationals and a four-day Test follow.